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Publication numberUS6642402 B2
Publication typeGrant
Application numberUS 10/178,014
Publication dateNov 4, 2003
Filing dateJun 21, 2002
Priority dateApr 30, 2001
Fee statusPaid
Also published asCA2445856A1, CA2445856C, EP1390375A1, EP1390375A4, EP1390375B1, US20030045737, WO2002088153A1
Publication number10178014, 178014, US 6642402 B2, US 6642402B2, US-B2-6642402, US6642402 B2, US6642402B2
InventorsKarin A. Voll Barclay, Jeffrey M. Sullivan, Dawn A. Arkin, Fredric R. Askham
Original AssigneeBoulder Scientific Company
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Synthesis of bis (cyclopentadienyl) and bis (indenyl) ruthenium complexes
US 6642402 B2
A process for preparing a cyclopentadienyl or indenyl ruthenium complex by treatment of a cyclopentadienyl or indenyl compound with ruthenium trichloride dihydrate and magnesium powder in an alkanol at 10° C. to −30° C. is described.
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We claim:
1. A process for producing a cyclopentadienyl or an indenyl ruthenocene complex which comprises treating a cyclopentadienyl or an indenyl compound with ruthenium trichloride hydrate and magnesium powder.
2. The process of claim 1 wherein said treating of said cyclopentadienyl compound or said indenyl compound is accomplished in the presence of a C2 to C8 alkanol.
3. The process of claim 1 or claim 2 wherein said treating takes place at a temperature of 10° C. to −30° C.
4. The process of claim 2 wherein said alkanol solvent is ethanol.
5. The process of claim 1 wherein the mesh size of said magnesium powder is from about 50 mesh to about 200 mesh.
6. The process of claim 1 wherein the mesh size of said magnesium powder is from about minus 100 mesh to about 200 mesh.
7. The process which comprises:
(i) treating a C2 to C5 monoalkyl cyclopentadiene with ruthenium trichloride hydrate and magnesium powder,
wherein said treating is accomplished in the presence of ethanol and
wherein said treating takes place at a temperature of 10° C. to −30° C. to produce a reaction mixture;
(ii) agitating said step (i) reaction mixture at about 10° C. to about 15° C. for a time period appropriate to complete the reaction
wherein an ethanol solution of C2 to C5 ruthenocene is produced in situ in said reaction mixture; and
(iii) isolating said C2 to C5 ruthenocene from said step (ii) ethanol solution.
8. The process of claim 7 wherein said C2 to C5 monoalkyl cyclopentadiene of step (i) is ethyl cyclopentadiene and wherein said C2 to C5 ruthenocene of steps (ii) and (iii) is ethyl ruthenocene.
9. A process for producing ruthenocene which comprises treating cyclopentadiene with ruthenium trichloride hydrate in the presence of magnesium powder.
10. A method for producing ethyl ruthenocene which comprises:
(i) providing an ethanol solution of ruthenium trichloride hydrate;
(ii) providing a slurry of magnesium powder and ethyl cyclopentadiene in ethanol; and
(iii) adding said step (i) solution to said step (ii) slurry at a temperature of from about 10° C. to about −10° C.
wherein a reaction mixture containing an ethanol solution of ethyl ruthenocene is produced.
11. The method of claim 10 further comprising a step
(iv) isolating said ethyl ruthenocene from said step (iii) reaction mixture.

This application is a continuation-in-part of U.S. patent application Ser. No. 09/938,952 filed Aug. 24, 2001 now abandoned, which in turn is a continuation-in-part of U.S. patent application Ser. No. 09/845,627 filed Apr. 30, 2001 now abandoned.


This invention relates to bis(cyclopentadienyl) and bis(indenyl) ruthenium complexes which are useful in chemical vapor deposition (CV) and other procedures.


The state of the art relevant to this invention as of Jul. 17, 1997 is summarized in U.S. Pat. No. 6,002,036. A process for the synthesis of bis(alkylcyclopentadienyl) ruthenium complexes by treatment of RuCl3 hydrates and ethylcyclopentadiene or isopropylcyclopentadiene with zinc powder in an alcohol solvent at −30° C. to 0° C. is described.


The invention comprises synthesis of bis(cyclopentadienyl), bis(alkylcyclopentadienyl), bis(indenyl) or bis(alkylindenyl) liquid and solid ruthenium complexes by treating ruthenium trichloride hydrate and a cyclopentadienyl compound or an indenyl compound with magnesium powder in C2 to C8 alkanol, e.g., ethanol. The treating may be accomplished at a temperature from about 10° C. to about −30° C.


As used in this specification, the following terms have the meaning set forth:

(1) Cyclopentadienyl Compound

A compound of the formula

in which each R is independently hydrogen or a C1 to C10 alkyl group. C1 to C5 monoalkyl cyclopentadienyl compounds are preferred.

(2) Indenyl Compound

A compound of formula

in which each R is independently hydrogen or a C1 to C10 alkyl group. C1 to C5 monoindenyl compounds are preferred.


Ruthenium trichloride dihydrate, a cyclopentadienyl or indenyl compound, and an alkanol, preferably ethanol, are combined and treated with magnesium powder of about minus 100 (−100) to 200 mesh at low temperatures with an appropriate stir out. A bis(cyclopentadienyl) or bis(indenyl) ruthenocene may be isolated by filtration, followed by combination with an aliphatic or aromatic hydrocarbon solvent, preferably hexane or toluene, another filtration, and subsequent passage through a silica column. Final products, if solids, may be isolated in >99% purity in yields of about 65 weight percent by crystallization from a hydrocarbon solvent. High purity liquid products may be isolated by fractional distillation.

EXAMPLE 1 Ethyl Ruthenocene-Yellow Oil Product

Ruthenium trichloride dihydrate is dissolved in ethanol. The solution is cooled to −20 C. to −30° C. and 4.0 to 4.4 equivalents of ethylcyclopentadiene (EtCp) are added. Over the course of 1 hr to 1.5 hr, magnesium powder (minus 100 mesh) (3.0 equivalents) is added as the pot temperature is maintained at −10° C. to −30° C. The consequent reaction mixture is stirred out for about 19 hours at 10-15° C., or until gas chromatography analysis indicates that the reaction is complete. Thereafter, the reaction mixture is filtered, and the ethanol and unreacted ethyl cyclopentadiene are removed under vacuum. Nexane and 3.0 equivalents of Na2SO4 are added to the remaining slurry which is then stirred for 1-20 hrs. The solids are removed by filtration through Celite. The remaining yellow solution is distilled under vacuum to an oil. The yellow oil can be isolated in >99% purity with yields of 65%. Hexane is added back to the oil, followed by a filtration through Celite® or silica. A final run through a silica column may be appropriate to remove any color bodies.

Hexane is stripped from the yellow solution so produced. Pentane is added to the residual oil, and the product, (EtCp)2Ru, is crystallized at −30° C. After removal of the supernatant, the pentane is then pumped off under vacuum. More than one crystallization may be appropriate to enhance purity. This synthesis is illustrated by equation 1: 4.4 EtCp + RuCl 3 · 2 H 2 O 10 to - 30 C . EtOH 3.0 Mg Powder ( EtCp ) 2 Ru 94 g / mol 243.5 g / mol 24.3 g / mol 288 g / mol 4.576 mol 1.04 mol 3.12 mol 1.04 mol 430 g 253.2 g 75.8 g 300 g

Equation 1

Any cyclopentadienyl or any indenyl compound as defined herein may be substituted for ethylcyclopentadiene in Example 1.

Magnesium powder of any desired mesh size, preferably minus 100 (−100) to 200 mesh, may be used. Any C2 to C8 alkanol may be used instead of ethanol.

Alternatively, a preformed alkanol solution of ruthenium trichloride dihydrate may be added to a preformed slurry of magnesium powder and alkyl cyclopentadiene at a temperature of about 0° C. to

EXAMPLE 2 Unsubstituted Ruthenocene-Crystalline Product

A magnesium slurry was produced by adding 45.62 g of minus 100 (−100) mesh magnesium powder (made by READE) (1.88 moles, 3 equivalents) slowly to a 5 liter vessel containing 1.2L of ethanol (Filmex) at room temperature (25° C.). 323.00 g of 76.8% pure cyclopentadiene (3.75 moles) at a temperature of about −50° C. was added to the magnesium slurry, which was at room temperature, through an addition funnel. To this, a 0.35M solution of RuCl3*1.8H2O in ethanol (Filmex) (0.625 moles in 1.8L of ethanol) was added over a 2.5 hour time period, via addition funnel, between −10° C. and 10° C. The slurry turned sequentially from a grey color to brown to green to blue, and then back to grey/brown as each addition of ruthenium trichloride was made. The mixture was then stirred at a temperature of from 5° C. to 10° C. for 3 hours, and was then stirred out to room temperature overnight. The ethanol was then distilled off under rough pump, and about three to four liters of toluene was added back. The distillation was switched from rough pump to atmospheric pressure and was continued until a pot temperature of 110° C. was reached. The yellow solution was hot filtered (100° C.) through a cake of Celite® that had been washed with hot toluene (100° C.). The filtrate was concentrated by distillation until the yellow solution reached a volume of 650 mL. The yellow product crystallized out of the toluene solution as it cooled to room temperature. The yellow slurry was further cooled in a dry ice/acetone bath, and the light yellow crystalline solids were filtered on to a Buchner funnel, washed with 100 mL of hexane, and pumped dry giving 134.3 g of ruthenocene (93% yield from first crop).

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US6002036 *Mar 8, 1999Dec 14, 1999Kabushikikaisha Kojundokagaku KenkyushoProcess for producing bis(alkyl-cyclopentadienyl)ruthenium complexes and process for producing ruthenium-containing films by using the same
US6521772 *Sep 27, 2001Feb 18, 2003Praxair Technology, Inc.Synthesis of substituted ruthenocene complexes
US20020058106 *Aug 8, 2001May 16, 2002Tanaka Kikinzoku Kogyo K.K.Process for preparing a bis (alkylcyclopentadienyl) ruthenium, bis (alkylcyclopentadienyl) ruthenium prepared thereby, and chemical vapor deposition of a ruthenium film or ruthenium-compound film
US20020064948 *Mar 13, 2001May 30, 2002Tanaka Kikinzoku Kogyo K.K. (Japanese Corporatin)Preparation method of bis (alkylcyclopentadienyl) ruthenium
US20020065427 *Sep 24, 2001May 30, 2002Tanaka Kikinozoku Kogyo K.K.Organometallic compounds for chemical vapor deposition and their preparing processes, and processes for chemical vapor deposition of precious-metal films and precious-metal compound films
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US7893290Apr 13, 2010Feb 22, 2011W.C. Heraeus GmbhProcess for the preparation of bis(pentadienyl)-complexes of iron group metals
EP2383277A1Jun 16, 2010Nov 2, 2011Heraeus Precious Metals GmbH & Co. KGProcess for the preparation of bis (pentadienyl)-complexes of iron group metals
U.S. Classification556/136, 427/252
International ClassificationC07B61/00, C07F15/00, C07F17/00, C07F17/02
Cooperative ClassificationC07F17/00
European ClassificationC07F17/00
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